Emmanuel Macron launched his political party En Marche! – now La République en Marche! (The Republic on the Move!) – less than 18 months ago.

Now, not only has Macron himself become France’s youngest ever elected leader, but his party has dominated France’s parliamentary elections.

In yesterday’s second-round or run-off elections, it appears that La République en Marche! (LRM) candidates have won 350 of the 577 constituencies - fewer than projected, but this is a huge victory. It is one of the greatest landslides since Charles de Gaulle’s team won more than 80% of seats in elections after the collapse and repression of the student revolts in May 1968.

The major opposition party will be the centre right Les Républicains, but it will see its number of seats fall, from 199 to 137. The Parti Socialiste (PS), which had been in power since 2012, has been the biggest loser, going from 289 seats to 44 (and with it losing the vast public funding which, as in Australia, is based on votes received). Even the party leader, Jean-Christophe Cambadélis, lost the seat in Paris he had held for 20 years. While every existing party across the spectrum lost voters to LRM, it was above all the PS voters who deserted in droves.

The election was equally disastrous for the Front National of Marine Le Pen. After her historic high of 33.5% in the May Presidential Elections, she had high hopes of reaching the hurdle of 15 seats which increases a party’s speaking rights in the National Assembly. Instead the party vote tumbled to 13%, and it won only eight seats. Recriminations are open within the party who see its future as adopting the strident anti-elite and anti-EU messages that might appeal to angry leftist voters and others who see its popularity as based above all in tough stances on migrants and refugees, and on border security.

The PS has been fortunate to outpoll the hard left La France Insoumise (France Unbowed) headed by Jean-Luc Mélenchon to remain the largest party of the left. LFI is projected to win 16 seats – enough to form a parliamentary group – but, even with its Communist Party allies (10), it is not big enough to claim to be the main left-wing opposition force against Macron.

How did he do it?

The positive explanation is that he is a very smart man who has not put a foot wrong since running for President on a frankly pro-European platform. He gave Europe as well as France a shot in the arm with his decisive victory over Marine Le Pen, and has impressed French people with his inclusiveness and his willingness to stand up courteously but bluntly to both Trump and Putin. Who will forget that white-knuckle handshake with Trump? He has rejuvenated parliament: most of the LRM deputies are new to public office and younger: their average age is 43.

The negative explanation is worrying. The LRM candidates did so well because FN and LFI voters stayed away from the polls. Macron may find that he has a massive majority in the National Assembly – now half composed of political neophytes – but outside parliament awaits a majority of the citizenry sceptical of the supposed benefits of free-market reform.

Macron’s cabinet has already indicated the broad character of the government he will lead. This is a cabinet which balances men and women (11 each) – although the most senior positions are held by men - from a range of ideological backgrounds. It brings in capable people new to public office, and balances liberal economic policy with progressive attitudes to the environment and social issues.

The tough posts on the economy have gone to men from centre right parties – the Prime Minister Édouard Philippe and the Economy Minister Bruno Le Maire – while Macron has appointed a prominent ecologist Nicolas Hulot as Minister for the Environment and a Socialist Party Mayor of Lyon Gérard Collomb as Interior Minister. The most senior women are Defence Minster Sylvie Goulard, Labor Minister Muriel Penicaud and Health Minister Agnes Buzyn. It is a government with ideological parallels to those of former US President Barack Obama and Canadian Prime Minister Justin Trudeau.

A difficult task ahead

Macron faces challenges that have proved too great for his predecessors for forty years, and which confront most of Europe: what can be done about long-term double digit unemployment which hits at least 25% of young people? How can deep ‘communitarian’ rifts and mistrust be healed between unemployed, disaffected young people from migrant backgrounds, particularly North Africans? Macron's major plans are to loosen France's highly protective labour laws, and change pensions and unemployment benefits in the hope of both reducing the massive deficit and enabling employers to hire more employees.

The President’s greatest challenge will be how to achieve reform this without - in reality or in perception - undermining France's social protections. His task has been made more difficult by the low participation rate (43.5%), which makes it difficult for him to claim a popular mandate for radical change. It is clear that Macron’s voters were disproportionately very educated, employed residents of major cities, not the disaffected and unemployed of the suburbs and country towns.

Macron’s domination of parliament could give him a relatively free rein to push through his plans to loosen France’s extensive labour laws and change the welfare system on pensions and unemployment benefits. But he will be acutely aware of the large-scale street protests that forced him to compromise one year ago when he attempted similar reforms when a minister in the government led by Francois Hollande. While only 8% of the French workforce is unionised, organised labour has a long and successful history of collective action to protect entrenched benefits.

The majority of French people want Macron to succeed, but his honeymoon may be very short.